1. Field of the Invention
The present invention relates in general to deproteinization agents, and more particularly to a deproteinization filler which can remove proteins from a biological sample or the like.
2. Description of the Prior Art
In order to analyze amino acid in biological sample and/or trace the medicinal metabolism of the sample, a so-called "high speed liquid chromatography method" has been used. In fact, such method is widely used in the medical field and the like.
However, in order to deal with a large quantity of biological samples with high accuracy, troublesome and time-consumed analyzing procedure has been hitherto needed even though the high speed liquid chromatography method is used.
One of the reasons of such troublesome and time-consumed procedure is the presence of large quantity of proteins in the samples. That is, proteins have a tendency to interrupt the quantitative analysis for a target constituent in the sample and shorten the life of the analysis instruments. Thus, prior to making the substantive analysis, it is necessary to remove proteins from each sample.
In the medicinal metabolism, for removing proteins, two methods are commonly used, one being a method in which trichloroacetic acid is added to the sample and thereafter a centrifugal separation is carried out on the sample, and the other being a method in which extraction is carried out using organic solvent. However, also these methods require troublesome and time-consumed procedure.
Nowadays, in the field of blood analysis, so-called "blood non-touch analyzing procedure" and "throwaway of tested samples" have been highly desired for avoiding dangerous infection from contaminated blood.
In view of the above, there has been proposed a throwaway type cartridge which has an ultrafilter installed therein. However, in contrast with easier handling of the cartridge, usage of such expensive ultrafilter inevitably brings about increase in production cost of the cartridge. Furthermore, even though such throwaway type cartridge is used, satisfied time saving is not obtained in the analyzing procedure.
As is known, hydroxyapatite is an agent which exhibits a high protein removing ability and thus the agent is used as a column filler when the high speed liquid chromatography method is carried out. In this connection, Japanese Patent Application 2-45297 shows a method for producing a column filler which can remove proteins. In this method, phosphoric acid and calcium hydroxide are reacted to produce a slurry, and the slurry is spray-dried to produce an aggregate of hydroxyapatite. The aggregate is then molded and sintered to form the column filler. However, the column filter produced by this method fails to exhibit a satisfied performance. Japanese Patent First Provisional Publication 1-201015 shows an example in which hydroxyapatite having three dimensional network structure is used as a column filler for the liquid chromatography. That is, the hydroxyapatite is obtained from the reaction between secondary calcium phosphate and alkali. However, this publication fails to describe the protein removing ability which is needed for effectively removing proteins in a very short time.